[IA64] eliminate compile time warnings

This patch removes following compile time warnings:

drivers/pci/pci-sysfs.c: In function `pci_read_legacy_io':
drivers/pci/pci-sysfs.c:257: warning: implicit declaration of function `ia64_pci_legacy_read'
drivers/pci/pci-sysfs.c: In function `pci_write_legacy_io':
drivers/pci/pci-sysfs.c:280: warning: implicit declaration of function `ia64_pci_legacy_write'

It also fixes wrong definition of ia64_pci_legacy_write (type of `bus' is not
`pci_dev', but `pci_bus').

Signed-Off-By: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/include/asm-ia64/machvec.h b/include/asm-ia64/machvec.h
index c3e4ed8..a9c995a 100644
--- a/include/asm-ia64/machvec.h
+++ b/include/asm-ia64/machvec.h
@@ -347,9 +347,11 @@
 #endif
 #ifndef platform_pci_legacy_read
 # define platform_pci_legacy_read	ia64_pci_legacy_read
+extern int ia64_pci_legacy_read(struct pci_bus *bus, u16 port, u32 *val, u8 size);
 #endif
 #ifndef platform_pci_legacy_write
 # define platform_pci_legacy_write	ia64_pci_legacy_write
+extern int ia64_pci_legacy_write(struct pci_bus *bus, u16 port, u32 val, u8 size);
 #endif
 #ifndef platform_inb
 # define platform_inb		__ia64_inb